Side return extension steels · London
Side return extension steels in London
Calculations, approvals, propping, steel and making good for side return extension steels across London.
- Price fixed in writing once scope is agreed
- Building control arranged
- Temporary works and making good included
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
Side return extension steels in London: how it works
Side return extension steels are the beams and columns that replace the side wall of a terraced house's rear wing when the narrow passage beside it is built over. Sized by a structural engineer, they carry the wall, floor and roof loads above along the line of the old wall, so the kitchen and the infilled side return become one wide room.
We carry out side return extension steels throughout London, for homeowners, landlords and builders who need the structural part done properly. Coverage takes in Enfield Town, Sutton and Islington and everywhere in between. You get an itemised written quote that shows the calculations, approvals, steel, labour and finishing as separate lines.
Things to plan for
- Propping a side return is awkward because space in a narrow kitchen is tight and the infill side is often open ground. Props outside may stand on temporary pads or boards, set so they do not sink or shift in wet weather.
- The number of beams, columns and connections drives steel cost more than the length of the side return alone. Keep the calculations, any party wall paperwork and the completion certificate together for when the house is sold.
- Where the beam along the old side wall meets a beam across the main house, the junction carries a heavy point load. The engineer usually details a column or a bolted connection there, which needs a solid foundation beneath it.
- Bathrooms above outriggers are common, and their floors carry baths, tiles and water. The engineer allows for those loads, and any soil pipe or waste running down the side wall is rerouted before the wall comes out.
- The kitchen is usually out of use while the side wall comes down and the frame goes in, so many households set up a temporary kitchen elsewhere in the house. The rest of the property normally stays in use throughout the steel stage.
Four stages, one team
Look and measure
We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.
Design and price
Calculations come back from the engineer and we confirm your fixed written price, line by line.
Building control
We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.
Fit, inspect, finish
The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.
How much should I budget in London?
As a guide, budget £4,500–£10,900 including VAT for side return extension steelwork in London, based on published UK cost guides adjusted for London prices (+28%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Side return extension steelwork | £4,500–£10,900 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
| Party wall surveyor (agreed surveyor, per neighbour) | £1,150–£2,550 per neighbour | Schedule of condition and award where a neighbour dissents; serving notice alone, where the neighbour consents, costs far less (England and Wales only) |
| Temporary works and propping | £190–£640 | Props, spreaders, needles and sole plates for a typical opening, installed and struck |
| Steel column or post | £640–£1,920 per column | Column supplied and fitted with base and cap plates on a pad foundation |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Approvals in London
For London, building control is provided by the local council's building control team, or by a registered building control approver if preferred. We send them the engineer's calculations with a building notice or full plans application and book the inspections. Work done without approval can cause problems at sale and is far dearer to put right later.
If the beam bears into a wall you share with a neighbour, the Party Wall etc. Act 1996 applies, and a party structure notice must be served at least two months before that work starts. We arrange this through a party wall surveyor.
Side return extension steels by town
- Brent
- Islington
- Westminster
- Bexley
- Barking
- Archway
- Sutton
- Croydon
- Ilford
- Enfield Town
- Harrow
- Tottenham
- Walthamstow
- Dagenham
- Becontree
- Romford
- Hayes
- Wembley
- Fulham
- Edmonton
- Southall
- Putney
- Battersea
- Purley
- Peckham
- Chingford
- Uxbridge
- Wimbledon
- Stamford Hill
- Brixton
- Hounslow
- Finchley
- Cricklewood
- Mitcham
- Feltham
- Acton
- Beckenham
- Chelsea
- Streatham
- South Croydon
Local questions answered
Can I stay at home while the work is done in London?
Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.
Which towns in London do you cover?
We cover towns including Brent, Islington, Westminster and Bexley, plus the villages and smaller towns around them.
Do I need planning permission for a side return extension?
It depends on the house and where it is. Some side return infills can be built under permitted development, but the rules for side extensions are restrictive, and conservation areas and listed buildings add further controls. Check with your local planning authority or architect before committing to a design.
Can the steel beam be left exposed in a side return?
Yes, and many people like the look of exposed steel under a glazed roof. It usually still needs fire protection, so it is coated with an intumescent paint system to the specified thickness, then finished in your chosen colour. The engineer and building control confirm what protection is required.
Why does a side return need columns?
Columns are used where two beams meet or where there is not enough solid wall to carry the end of a beam. The column takes the concentrated load down to a pad foundation in the ground. Sometimes it can be hidden in a wall nib or boxed in neatly.
Do I need a party wall agreement for a side return extension?
In England and Wales it is very likely. Building on or near the boundary, excavating close to the neighbour's foundations or cutting into a shared wall can all be notifiable under the Party Wall etc. Act 1996. Notices are arranged through a party wall surveyor on your behalf, and we do not give legal advice.